The invention relates to a fire extinguisher including a pyrotechnic gas generator.
A fire extinguisher is conventionally in the form of a tank containing an extinguishing agent that is to be delivered onto the zone of a fire in order to extinguish it. Several types of extinguisher are known in the state of the art.
In particular, extinguishers are known that are permanently pressurized, comprising a tank under gas pressure containing the extinguishing agent, or else a gas cylinder under pressure in communication with the chamber in which the extinguishing agent is present. In that type of extinguisher, the extinguishing agent or the propellant gas for propelling the extinguishing agent is stored permanently under pressure. In order to use extinguishers having a pressurized gas cylinder, the gas cylinder is initially actuated by the user in order to release the pressurizing gas into the chamber containing the extinguishing agent, and then the extinguishing agent as put under pressure in this way is delivered onto the fire zone by manual actuation.
Extinguishers that are permanently pressurized present certain drawbacks, such as in particular the need for a certain number of monitoring and verification operations (periodic weighing). In addition, since the pressure of gas varies with temperature, the operation of extinguishers of that type is temperature-sensitive.
Another drawback is that while delivering the extinguishing agent, the volume available for the gas increases and thus the pressure of the gas decreases, thereby reducing the rate at which the extinguishing agent is delivered, and consequently reducing the effectiveness of the extinguisher. In an attempt to mitigate that drawback, it is possible to increase the pressure available at the beginning of delivering the extinguishing agent, however for safety reasons such a solution makes it necessary to overdimension the extinguisher, and consequently to increase its overall size and also its cost price.
As an alternative to extinguishers that are permanently pressurized, a second type of extinguisher has been proposed that includes a pyrotechnic gas generator. The pyrotechnic gas generator enables combustion gas to be produced that serves to pressurize the chamber in which the extinguishing agent is present, and consequently to deliver said extinguishing agent onto the fire zone. Such extinguishers with a pyrotechnic gas generator give relatively high performance and serve to mitigate some of the drawbacks of extinguishers with permanent pressurization.
In particular, Document DE 20 2006 002 892 discloses an extinguisher having a pyrotechnic gas generator presenting architecture that is relatively close to the architecture of permanently pressurized extinguishers that make use of a cylinder of gas under pressure. In that document, the gas generator is actuated by a manual striker situated at one end of the tank and it communicates with the load of extinguishing agent via a first dip tube. A second dip tube is connected to the outlet orifice and serves to direct the extinguishing agent towards the outlet orifice. A lance having a trigger communicates with the outlet orifice and enables the extinguishing agent to be delivered into the outside medium after actuation by a user.
The extinguisher of Document DE 20 2006 002 892 presents certain advantages, but nevertheless it would still be desirable to be able to simplify its structure, in particular in order to reduce the cost of fabricating such an extinguisher. Furthermore, the rate at which the extinguishing agent is delivered is not always optimal in that type of extinguisher.
There thus exists a need to have fire extinguishers available that present a structure that is simplified and a fabrication cost that is reduced.
There also exists a need to have fire extinguishers available that present an optimized flow rate for delivering the extinguishing agent.